Vacuum cleaner



Nov. 10, 1936. c BROCK 7 2,060,168

VACUUM CLEANER Filed May 4, 1934 6 Sheets-Sheet 1 INVENTOR.

E. C'ldrefia'e H. Brae/r,

BY 4MW yimvw.

ATTORNEYS.

C. A. BROCK VACUUM CLEANER Nov. 10, 1936.

Filed May 4, 1934 6 Sheets-Sheet 2 INVENTOR. 6714712276: 14. Brae? ATTORNEYS.

C. A. BROCK VACUUM CLEANER Filed May 4, 1934 6 Sheets-Sheet 5 INVENTOR.\ Clarence f7. Brae F.

ATTORNEYS.

Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE mesne assignments,

to Rexair Corporation,

Detroit, Mich., a corporation of Michigan Application May 4, 1934, Serial No. 723,840

31Claims.

This invention relates generally to that class of articles commonly known as'vacuum cleaners commonly employed for removing dust or other foreign material from carpets, upholstery, or the like, although the construction herein provided, either whole or in part, may be advantageously employed in the separation of foreign material from air or other gas and accordingly, while the embodiments of. the invention disclosed in the accompanying drawings are limited to the application of the various features to a vacuum cleaner of a type adapted for household use, and the description of such features is limited to such use, it is to be understood that the invention is not limited solely thereto.

Objects of the invention include the provision of a vacuum cleaner structure that is light in weight, eflicient in operation and pleasing in general appearance; the provision of a vacuum cleaner of the type wherein the cleaner nozzle forms a unit independent of the air pump and dust separating mechanism which combine to form a second unit connected to the nozzle unit by means of a flexible tube, the flexible tube being connected to the second unit adjacent the base thereof to permit the second unit to be pulled over a supporting surface by a force exerted on the flexible tube without unduly endangering tipping over of the second unit by reason of such force; the provision of a vacuum cleaning structure in which the air first entering the structure is first acted upon by a mechanically driven separator element to separate out the bulk of foreign material carried by the air and to deposit it into a non- 5- straining compartment from which it may be easily and quickly removed by the operator at suitable intervals; and the provision of a vacuum cleaning. structure provided with both mechanically driven air separating means and a stationary filtering element thus doubly insuring the separation of all foreign material from the air processed by the structure.

Other objects include the provision of a mechanically driven air separator element of new and novel construction; the provision of a mechanically driven air separator element including a generally circular sheet metal shell formed to provide alternately inwardly and outwardly facing grooves, the bottoms of the outwardly facing grooves being provided with relatively narrow slits therein for the passage of air therethrough.

Other objects of the invention include the provision of a rotatable air separator element and a separator cleaner element freely rotatable relative thereto and extending into close but spaced relation with respect to the discharge face thereof the provision of a cage or cup-shaped air separator element provided with suitable means for driving the same and a separator cleaner element within the separator and freely rotatable relative thereto, the cleaner element having portions extending into close but spaced relation with respect to the inner face of the separator element so as to be caused to be driven by the air set in motion by the separator element, the cleaner element having appreciable mass whereby during variations in the speed of rotation of the separator element relative rotation will occur between the separator element and the cleaner element to cause said portions to sweep the inner face of the separator element; and the provision of a rotatable shaft having an air separator element secured thereto, a. freely rotatable separator cleaner element within the separator element, and a novel form of lubricating means for the separator cleaner element.

Other objects of the invention include the provision of a vacuum cleaner or thelike, including a casing having an inlet and an outlet, a rotatable air separator element between the inlet and the outlet, an air pumping mechanism between the air separator element and the outlet, means for driving the pumping mechanism and the air separator element, and a second casing in open communication with the first casing between the air separator element and the inlet and providing a zone of quiescence for receiving and storing foreign material separated from the air by the air separator element; the provision of a structure as above described in which a stationary filtering element is provided between the pumping mechanism and the outlet in order to trap any foreign material that may escape through the rotatable separator element as well as to muiile the sound of air escaping'from the device.

Further objects include the provision of a vacuum cleaner or related structure having certain novel mechanical features of construction.

The above being among the objects of the present invention, the same consists in certain novel features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawings and then claimed, having the above and other objects in view.

In the accompanying drawings which illustrate suitable embodiments of the present invention and in which like numerals refer to like parts throughout the several different views,

Fig. 1 is a side elevational view of a vacuum cleaning apparatus showing a nozzle member or device operatively connected therewith.

Fig.2 is an enlarged, partially broken, partially sectioned view of the vacuum cleaner mechanism indicated at Fig. 1, the section being taken centrally through the apparatus in a plane parallel to the view indicated in Fig. 1.

Fig. 3 is a horizontal sectional view taken on the line 3-4 of Fig. 2.

Fig. 4 is a horizontal sectional view taken on the line 4--4 of Fig. 2 and illustrating the construction of the spider member at the bottom of the rotatable air separator element.

Fig. 5 is a fragmentary, horizontal, sectional view taken on the line 55 of Fig. 2 and particularly illustrating the construction of the sealing fan for the rotatable air separator element.

Fig. 6 is a transverse sectional view taken on the line 6-6 of Fig. 2.

Fig. '7 is a side elevational view of the rotatable air separator element.

Fig. 8 is an enlarged, fragmentary, horizontal sectional view taken on the line 88 of Fig. 7.

Fig. 9 is a fragmentary, horizontal, sectional view taken. on the line 9-9 of Fig. 2 illustrating the construction of the driving motor so as to permit the fiow of air therethrough.

Fig. 10 is'a horizontal view taken on the line Ill-l0 of Fig. 2 and showing the final filtering and noise bafliing element partially broken away to better illustrate the construction thereof.

Fig. 11 is a fragmentary, vertical, sectional view taken on the line I l-l i of Fig. 2 and better illustrating the construction of the driving motor.

Fig. 12 is a fragmentary, end elevational view of the apparatus shown in Fig. 2, taken from the right hand side thereof.

Fig. 13 is a fragmentary, vertical sectional view taken on the line- I3l3 of Fig. 12 and better illustrating the air inlet for the device.

Figs. 14, 15 and 16 are fragmentary, sectional views taken centrally through the rotating air separator element and associated parts illustrating respectively different modifications of sealing means between the open edge of the separator element and its cooperating casing wall.

Fig. 17 is a partially broken, partially sectioned, side elevational view of a modified form of the structure shown in the preceding figures in which stationary filtering elements are provided in the path of air flow between the rotatable separator element and the air pumping mechanism.

Fig. 18 is a partially broken, partially sectioned, plan view of the structure shown in Fig. 17.

Fig. 19 is an enlarged, fragmentary, vertical, sectional view taken on the line i9l9 of Fig. 18 and illustrating one of the fixed filtering elements positioned in the path of air flow between the rotating filtering element and the air pumping mechanism, the mechanism at the top of the filtering element being shown in a position to block the fiow of air between the rotatable air separator element and the pumping mechanism.

Fig. 20 is a horizontal sectional view taken on the line 20-20 of Fig. 19. I

Fig. 21 is a fragmentary, sectional view taken in the same plane as Fig. 19 but illustrating the mechanism at the top of the filtering element in its normal operative position permitting air to flow beween the rotatable air separator element and the pumping mechanism through the stationary filtering element.

Referring particularly to Figs. 1 and 2, it will be noted that the vacuum cleaner there illustrated comprises a main casing indicated generally at 30 providing a housing for the operating parts of the structure and an associated casing 32 of pail-like formation which serves as a receptacle for the dust and other foreign matter separated out by the cleaner. The casing portion 30 includes a central main body portion 34 internally formed to provide a relatively large cylindrical opening 35, an upper frame member 36 at the upper end of the body member 34 and suitably secured thereto, an upper housing member 38 surmounting the frame member 36 and suitably secured thereto, a lower frame member 40 suitably secured to the lower face of the main body member 34 as by means of screws 42, and a bottom cap or cover 44 hingedly secured to the lower frame member 42 by means of a hinge pin 46 and releasable latch mechanism indicated generally at 48. As best illustrated in Figs. 10, 12 and 13, the bottom frame member 40 and bottom cover member 44 are formed to provide a horizontally outwardly projecting boss 50 providing an air inlet opening 52. The opening 52 communicates interiorly of the lower cap 44 and lower frame 40 with an upwardly curving passage 54 which communicates at its upper end with the lower end of a passage 56 formed integrally in the main body portion 34 and extending from the bottom to the top thereof. The upper end of the passage 56 communicates through a suitable opening in the top frame member 36 with a passage 58 formed in the upper housing member 38 and opening into the hollow exterior thereof in a horizontal direction as at 60, as is seen in Figs. 2 and 6.

It will also be noted from an inspection of Figs. 2, 3 and 6 that the main body member 34 is formed to provide a second vertically extending passage 62 extending from the top to the bottom thereof.

The upper housing member 38 is provided with a flanged portion 64 which extends over the upper end of thepassage 62 and a switch element 65 suitably mounted within the passage 62 is provided with an actuating element 66 which projects up through the flange 64 so as to position it in readily accessible position to the operator'of the cleaner. The switch 65 controls an electric circuit including wires 68 suitably connected with the driving motor of the cleaner in a manner not shown and then projecting outwardly through a side wall of the lower frame member 40 in the form of a cord 10 as illustrated in Fig. 1 and provided with a conventional pronged connection member 12 at its extremity for connection with a suitable electric socket.

As also illustrated best in Figs. 2, 10 and 12, the lower frame member 40 and lower cap 44 are formed to provide between them an outlet opening 14 which leads into the interior of the cap 44 through a pocket 16 formed within the cap 44 and in turn communicating through an opening 16 leading to the interior of the cap 44 along the bottom thereof. As best illustrated in Figs. 2, 10, and 11, the lower cap member 44 is provided with an integral inner wall forming an upwardly opening pocket 82 therein, the purpose of which will hereinafter be described, and formed on the inner side walls of the cap 44 and the outer sides of the wall 80 are a plurality of spaced posts or fins 84, the upper ends of which terminate above the upper edge of the opening 18 and form shoulders for supporting a filtering and sound absorbing element indicated generally at 86 which extends between the outer walls of the cap 44 and the walls 80 so that all air discharging through the discharge opening 14 must pass through it. This filter element 86 preferably comprises a bottom layer 88 of woven wire screen to add rigidity to the structure, a layer 90 of relatively loose felt or material of like character upon which is positioned'a plurality of superposed sheets 92 of suitable fabric serving as a filtering medium. A

plurality of such sheets 92 are employed so that leave a clean sheet for continued operation of the device.

Both of the openings 52 and 14 are internally threaded for removably receiving the cooperating end 94 of a flexible tube 96, the opposite end of which is connected to the preferably rigid hollow wand or handle 98 of a suction nozzle member I80 as illustrated in Fig. 1 and which may be of any suitable type. Ordinarily, of course, the end 94 is connected to the opening 52 so that dust laden air may be withdrawn through the nozzle I into the cleaner for the purpose of separating the air from the dust but, under some conditions, it may be desirable to remove the nozzle I00 from the wand or handle 98 and substitute a blower type of nozzle (not shown) in its place in accordance with the conventional practice, and connect the end 94 with the opening I4 so that air may be blown through the tube 96, rather than sucked through-it, so as to enable the device to be used for purposes other than dust separation. Ordinarily, air is prevented from discharging horizontally outwardly through the opening 14 along the floor or supporting surface by means of a cap member I04 pivotally mounted on the lower frame member 40 as at I06 (see Fig. 12), this cap member being generally cup-shaped in formation with its .open end facing the opening 14, and the walls thereof are cut away at. the upper side thereof so that air issuing from the opening 14 will strike the bottom of the cup I04 and be directed upwardly away from the floor. This is for the. purpose of preventing the discharge of air from the device from disturbing unswept dust on the floor and also to prevent the issuing stre of air from blowing against and thus discomforting the operator of the cleaner. When it is desired to employ the cleaner as a 'blowerthe cap I04 is swung upwardly to the position indicated in dotted lines in Fig.12 thus permitting the end 94of' the flexible tube 96 to be connected into the opening 14 instead of the opening 52. Y L

Positioned centrally of the cylindrical opening 35 within the main body, portion 34 is a vertically extending shaft IIO the upperend of which projects into the upper portion of the hollow interior of the. top housing member 38 and the lower end of which projects downwardly'into the pocket 82' formed in the bottom cap 44. Suitably secured to the lower end of the shaft H0 is the armature II2 of an electric motor including a field element indicated generally at I I4. .The field element I I4 is supported within and located by an open ended ring II6 formed integrally with the transverse wall II8 of the lower frame member 40, the wall H8 sealing the space between the main body member 34and the ring I I6. Grooves I20 formed in the outer periphery of the field element II4 provide ducts through. which air processed by the cleaner may flow downwardly-to the discharge opening I4 through the filter element 86, and in thus flowing through the grooves I20 serves to cool the electric motor.

As illustrated in Fig. 11, arms I22 formed integrally with the ring H6 at opposite sides thereof extend downwardly into the pocket 82 where they not only form supports for the electric motor brushes I 24 but also carry the ring member I26 at their lower ends within the pocket 82. A ball bearing assembly I28 of the type adapted to take both radial and thrust loads is vertically slidably received within the ring I26 and is constantly urged upwardly therein by the coil spring I30-compressed between the lower face of the outer race of the bearing I28 and the cap I32 for the bottom of the ring I26. A suitable seal I34 of conventional construction is provided between the shaft H0 and the upper edge of thering I26 to seal the bearing I28 against contact with foreign material. The

hearing I28 as thus formed supports the shaft 2 .IIO as well as the weight of the armature H2 and other parts carried thereby and to be later described. The resilient support of the bearing I28 serves to cushion any shock to which the parts may be subjected and to eliminate any binding tendencies of the shaft bearings.

'The upper frame member 36, as best illustrated in Figs. 2 and 5, is formed to provide a transverse wall I36 at the top of the cylindrical opening in the main casing 34. 'The wall I36 is downwardly stepped as at I38 to provide a circular upwardly opening recess I40 therein concentric with the shaft H0. The bottom wall of the recess I40 is centrally cutaway to provide openings I42 for the flow of air therethrough, and centrally of the opening I42 a ring I44 is formed concentric with the shaft H0. A plurality of angularly spaced arms I46 formed integrally with the ring I 44 and the bottom wall of the recess I 40 serves to support and locate the ring. I44 without materially restricting the flow of air through the opening I42. Received within the interior of the'ring I44 is a bearing assembly I 48 for the upper end of the shaft I I0.. .Suitable dust seals co-act between the upper and lower ends of the ring 44 to seal the hearing I 48 against contact with foreign material. I

A pump structure of the multi-stage type is provided within the interior of the main body portion 34 for causing a flow of air through the device between the inlet and outlet. thereof. In the particular construction shown the pumping *mechanism is of the four-stage type and, ac-

of which extend into inwardly spaced relation with respect to the wall of'the cylindrical opening 35 formed within the main body portion 34.

The lower plate member I52 of each rotatable pump element closely but slidably receives the shaft IIO centrally thereof but the inner edge of the upper plate member I54 of each rotatable pump element terminates in outwardly spaced relationwith respect to the axis of the shaft H0 soas to provide an opening I56 Between its inner edge and the shaft II8 through which air may flow downwardly to the space between the plate members I52 and I54. The plate members I52 and I54 are maintained in spaced relation with respect to each other and rigidly secured together by means of a plurality of spirally arranged blades I58 positioned between them, the blades I58 being arranged in generally spaced relation in the manner illustrated in Fig. 6. Upper and lower edges of each blade I58 are provided at intervals with tongues I60 which project through cooperating openings in the plates I52 and I54 and are bent over the remote faces of the plate members so as to lock the blades and the plate members together into a unitary structure. Any other suitable means of securing these parts together may be employed but, in view of the fact that they are preferably made of relatively light gauge metal, this method of securement will be found to-be amply sufficient for all practical purposes and provides an economical method of assembly.

The various rotatable fan elements thus described are secured in properly axially spaced position and in driving relation to the shaft III! by means of a plurality of sleeve sections or collars I62 slidably received on the shaft Ill) between each of the rotatable fan elements and beyond the ends of the opposite end ones thereof. The lower sleeve I62 abuts against a shoulder I64 formed on the shaft III) immediately above the armature H2 and means which will hereinafter be described, are provided at the upper end of the shaft for forcing all of the sleeves I62 downwardly to thus clamp the inner margin of each plate member I52 between the ends of the cooperating sleeves I62. To stiffen the connection between each rotatable pump element and the shaft H0 and to enhance the driving engagement therebetween it is preferable to position a washer member I66 between the end of each sleeve I62 and the cooperating face of the corresponding plate member I52.

A stationary pump element is positioned between each adjacent pair of rotatable pump elements and each of these stationary pump elements comprises a lower annular plate member -I68 and an upper annular plate member I16 positioned in axially spaced relation with respect thereto and normal to the shaft III). The

upper plate member I10 adjacent its center extends into close but slightly spaced relation with respect to the corresponding sleeve I62 on the shaft IIO so as to substantially prevent the fiow of air between its inner edge and the sleeve. Its outer edge or periphery extends into substantially the same spaced relation with respect to the wall of the cylindrical opening 35 as the plate members I52 and I54. The lower plate member I 68 at its inner edge is materially spaced from the cooperating sleeve I62 on the shaft IIO so as to provide an opening I12 therein permitting air to flow downwardly therethrough from between the plates I68 and I10. The outer periphery of each plate I68 is closely but slidably received within the cylindrical opening 35 formed so as to prevent the passage of air between its periphery and the wall of such opening. The plate members I68 and I10 are secured together in spaced relation by means of a plurality of blade elements I14 of the general shape indicated in Fig. 6 and secured thereto in the same general manner as the blades l58 are secured to their cooperating plate members I52 and I54 as previously described.

The stationary pump elements thus described are suitably secured in properly axially spaced relation between each pair of rotatable pump elements in the following manner. A circular band I16 lying in contact with the wall of the cylindrical opening formed within the main body portion 34 is positioned between thev peripheral margins of each adjacent pair of plates I68 and above and below the upper and lower plates I68, and these ring members I16 are clamped axially of each other so as to clamp the peripheries of the plate members I68 between them. In view of the fact that no stationary pump element of the character above described is positioned below the lower rotatable pump element on the shaft III], a member I18 is provided which substantally seals the space between the wall of the pump chamber and the shaft I I0 except for openings I formedtherein adjacent its periphery. The member I18 which is formed from sheet metal is itself located and secured in position by having its marginal outer edge portions clamped between the lowermost ring I16 and the shoulder I82 formed on the interior face of the main body portion 34.

In order to direct air flowing through the opening I42 in the wall I36 into the central opening I56 of the uppermost rotatable pump element, a

, plate member I 84 is positioned above the upper ring I16 and provided with an opening I86 at its center about the ring I44 in alignment with the opening I56. The upper frame member 36 is provided with a downwardly projecting annu lar flange I88 which fits within the upper end of the opening 35 in the pump casing and bears against the periphery of the plate member I84,

and when the frame member I36 is secured to the main body portion I34 provides the necessary force for clamping all of the rings I16 axially against the cooperating plate member I68 and the lower ring member I16 downwardly to clamp the lower plate member I18 against the shoulder I82, thus fixing all of these parts in their operative relation.

With the construction as thus far described it will be apparent that when the shaft III] is rotated air from the interior of the upper housing member 38 will flow downwardly through the opening I42 in the wall 36, through the opening I86 in the plate member I84, and through the central opening I58 in the upper rotatable pump element to the interior of such pump element. Such air received within the upper rotatable pump element will be forced outwardly by the blades I58 thereof, due to the rotation of such pump element, and discharged from the outer edge thereof. The air thus discharged from the outer edge of the upper pump element will be drawn downwardly into the space between the upperplate member I10 of the upper stationary pump element and the inner wall of the main body portion 34 and then will flow inwardly through the upper stationary pump element to the central opening I12 formed in the lower member I68 thereof and while flowing therethrough, because of the shape of the blades I14 thereof, will be directed to the opening I 12 in a 'radial direction so as to prevent whirling of the air. The air thus passing downwardly through the opening I12 will be directed downwardly through the opening I 56 in the upper plate member I54 of the rotatable pump element immediately therebelow which will thereupon cause it to be ejected from the outer periphery thereof and it w ll then flow downwardl; into the next stationary pump element. The air is thus directed bulk of the foreign material is removed from the to the interior of each rotatable pump element and ejected therefrom and led into the outer portion of the next adjacent stationary pump element through which it flows and is discharged at its centralfportion downwardly into the interior of the next rotatable pumping element, the pressure of the air being increased as it flows consecutively from one rotatable pump element to the next. In this manner and by using a plurality of stages in the pump a high degree of suction is-made apparent at the inlet opening 52 and air is caused to be circulated between the inlet and outlet openings 52 and II, respectively, through the casing 30.

While the filtering element 86 previously ,described within the bottom cover 44 will filter the air passing through it to the discharge opening ll, its function in this respect is more or less incidental to its principal function of silencing the exhaust of air through the outlet opening, its filtering function being limited entirely to intercepting a very limited amount of dust particles which inevitably find their way through the main separator element of the device as otherwise it would soon become so plugged with foreign material as to seriously interfere with the proper operation of the cleaner and require frequent cleaning to maintain its efficiency. The

air flowing through the device prior to the time the .air reaches the pumping mechanism previously described. This is accomplished in the following manner.

An inverted cup-shaped sheet metal rotatable separator element 200, best shown in detail in outside toward the inside. The dust laden air to be processed by the element 200 in coming into contact therewith brings. the dust particles carried thereby into the range of the centrifugal force of the element 200 which causes the dust particles, because of their relatively greater weight as compared to the air, to be thrown outwardly away from the element 200, and substantially only air that has been released from its dust contents is drawn through the slots 2I0. Because the air is drawn into the grooves 208 before passing through the slots 2|0, the dust particles in the air are subjected to the same angular speed as the periphery of the element 200 before being caught in the high velocity air stream passing through the slots H0, and this permits them to be thrown outwardly from the Figs. 7 and 8, is secured .by a screw 202 as illustrated in Fig. 2 to the upper end of the shaft I I0 in concentric relation therewith. The bottom of the cup, or'in other words, the upper end of the element 200 is closed except for an opening through which the screw 202 projects, and the metal of the member at the lower open end thereof is preferably turned outwardly as at 204 to provide an annular flange to impart added stiffness to the structure. The sidewall or periphery of the element 202 is formed to provide a plurality of closely adjacent alternately inwardly facing grooves 206 and outwardly facing grooves 208 therein, the grooves 206 and 208 extending in spiral or helical direction with respect to the axis of the element 200. The bottom of each of the outwardly facing grooves 208 is centrally slotted over the length thereof as at 2l0, the slots 2i0 preferably being in the neighborhood of .015 of an inch in width. Atrib 2l2 is preferably formed midway the length of the grooves I 208 and 208 particularly so as to interrupt the continuity of the slots 2 i0 from the bottom to the top of the cup or separator element as otherwise, where the element 200 is of relatively deep construction, the centrifugal force acting upon the severed portions between the slots 2l0 might cause such portions to bend outwardly and increase the width of the central portions of the slots 2l0 to an undesirable degree. The air separator 200 thus formed is similar in result to that disclosed and claimed in United States Patent No. 1,420,665, issued June 27, 1922, to, John W. Newcomb, but is more economical to manufacture than the form therein shown and results in more efllcient operation.

It will be understood that in the operation of the air separator element 200 itis caused to rotate about its axis at a relatively high speed and air is caused to flow through it in the direction of the ket 224.

element 200. The conical effect of the element 200 aids in this effect in that it tends to cause the dust particles to be drawn downwardly toward the base thereof and discharged outwardly from the lower edge thereof away from the direct path of flow of air through the element 200.

Theshaft H0 and consequently the rotatable fan elements and the separator element 200 turn in the direction of arrow 2 indicated in Fig. 3 and, accordingly, in order to enhance the centrifugal effect of the separator 200 on the particles of dust being carried by the air flowing to it, the opening 60 connecting the inlet duct 58 with the hollow interior of the upper housing member 38 is positioned so as to direct the air flowing out of it in a tangential direction with respect to the outer surface of the element 200 and in the direction of'rotation thereof as indicated best in Fig. 3.

Referring now to Figs. 2 and 3, it will be noted that the left hand side of the upper frame member 38 is formed to provide a relatively large opening 220 therein and its bottom face surrounding the opening 220 is provided with a downwardly facing groove 222 in which an annular gasket 224 is seated. As previously described, the casing 32 is more or less pail-shaped and its upper edge is of a diameter to be received within the groove 222 against the lower face of the gas- The upper housing member 38 is extended over the casing 32 so as to provide .a hollow cap for the same and its outwardly flanged lower edge is secured to the upper face of the frame member 38 by screws 226. The hollow interior of the upper housing member 38 provides a passage 228 connecting the space over the casing 32 with the space surrounding the separator element 200. To enhance the flow of dust particles from the periphery of the separator element 200 to the space over the casing 32 thepassageway 228 is'preferably' arranged in an approximately tangential relation with respect to the periphery of the separator element 200 as indicated in Figs- 3. This also aids in lessening swirling and circulating of air in the passageway 228 and over the top of the casing 32.

With the construction thus the dust and other foreign material which is thrown outwardly away from the periphery of the separator element 200 by reason of the rotation thereof is directed through the passageway 228 to above the casing 32, and because of the fact that the. air within the casing 32 and in the upper housing member 30 above it is dead air, or air in a state of quiescence, the dust particles will separate out of such air by gravity and become deposited in the bottom of the casing-32. v made readily removable from the rest of'the apparatus in order to permit its periodic removal to empty it of the dust collected therein. The means permitting this comprises a pair of latch members 230 pivoted to opposite sides of the housing member 38 by pins 232, the lower ends of the latch members 230 being hook-shaped to releasably engage the peripheral locking flange 234 extending circumferentially about the casing 32 adjacent the upper end thereof.

In order to centralize the bottom of the cleaner element 208 with respect to the shaft H0 and to aid in supporting it thereon, the shaft IIU, as indicated in Fig. 2, is provided with a spider member 236 the rim of which is stepped for cooperative engagement with the lower edge and flange 204 of the separator element 200. The lower outer edge of the rim of the spider member 236 extends into close but preferably spaced relation to the upper edge of the shoulder I38 on the wall I36 so as to prevent the flow of unfiltered air from within the upper housing member 38 to the pumping mechanism without Passing through the separator element 200. If mly a single stage pump of the type described was employed for forcing air through the device the question of sealing at this point would be relatively simple due to the fact that in such case the air pressure on both sides of the separator element 200 would be substantially equal, the velocities only being different, but in a case as shown where the pumping element is of a multi-stage type the pressure on the outside of the separator element is considerably greater than the inside thereof and consequently means must be provided -for preventing the fiow of unfiltered air between the outer edge of the spider member 236 and the wall I36.

In order to eliminate the friction of rubbing parts at this point I prefer to employ the construction illustrated in Figs. 2 and 5 which consists in providing a plurality of radially directed, angularly spaced fan blades 238 on the lower face of the spider member 236 the ends of which blades are located in the recess I 40 below the rim of the spider 236. The result of this construction is that as the separator element 200 rotates the fan blades 238 rotate with it and act to force clean or processed air from the interior of the separator element 200 outwardly through the space between the rim of the spider 236 and shoulder I38 on the wall I36. Preferably, the amount of force exerted on the air by the blades 238 is just sufi'icient to balance or slightly over-- balance the diiference in pressure between the inner and outer sides of the separator element 203 tending to force unseparated air through this space. By this means air is prevented from entering the pumping mechanism except it first pass through the separator element 200 which removes the foreign-material therefrom and, in

view of the fact that no rubbing contact is provided between the parts, an extremely efficient construction is provided.

Again referring to Fig. 2, it will be noted that the hub of the spider 236 abuts at its lower end against a collar 240 surrounding the shaft IIII between it and the inner race of the bearing I48, and the lower face of the inner race of this bearing abuts against the upper end of the uppermost sleeve I62 previously described. A nut 242 threaded on the shaft I I0 immediately above the spider 236 acts to draw the spider, sleeves I62 and 240 and inner race of the bearing I48 downwardly so as to clamp all of these members between the nut 242 and the shoulder I64 at the lower end of the shaft IIO, thus looking all of these parts to the shaft III! for equal rotation therewith.

From a practical standpoint in connection with the uses 'to which a vacuum cleaner, for instance, is employed, it may be considered that the separator element 200 removes all of the foreign material from the air processed by it. As a matter of fact, however, a very small percentage of the dust carried by the air passing through the device will find its way through the separator element 200, and I have found that there is a tendency for dust thus finding its way through the separator element 200 to collect on the inner walls of such element. While the amount of dust thus built up on the inner walls of the element 200 is relatively small, over a long and continued use of the device it continues to build up until it may become present insufficient quantities to interfere with the proper functioning of the separator element 200 as well as to endanger bursting ofthe same due to the added weight carried by it and subjected to high centrifugal forces due to the high rate of rotation of the separator element during operation. To positively prevent the building up of such deposits within the separator element 200, a separator cleaner element indicated generally at 243 is provided on the interior of the separator element 208. As indicated best in Fig. 3, the separatorelement. 243 comprises a hub portion 244 and a pair of diametrically outwardly extending blades 246 the outer edges of which extend into close but spaced relation with respect to the inner peripheral wall surface of the separator element 200 as indicated in Fig. 2. The cleaner member 243 is freely rotatably received upon the upper end of the shaft IID above the nut 242 and for this purpose is provided with a suitable bushing 248.

With the construction thus described, when the machine is set in operation and the separator element 200 begins to revolve it will tend to cause the air within it to revolve with it and this will create a drag on the cleaner member 243 tending to rotate it with the cup 200. The cleaner member 243 and'particularly the vanes 24B are preferably made relatively heavy so that its inertia will resist changes in rotational speed. For this reason when the separator element 200 first starts to rotate the cleaner member 243 will lag behind it at'a slower speed and thus a difierence in .the rate of rotation of the separator element 200 and its cleaner member 243 will be effected which will cause the outer ends of the blades 246 to sweep the interior walls of the element 200 and thereby dislodge any deposit of dust which may have built up thereon to such an extent as to intersect the path of movement of the outer edge of the blades 246. For the same reasons as above set out, when the circuit to the electric driving motor for the shaft I I0 is opened and the shaft I In, together with the separator element 200 and other parts associated with the shaft IIO, reduce their speed, the inertia of the cleaner member 243 will tend to keep it rotating and will thus cause a difference in the rate of rotation of the separator element 20B and its cleaner member 243 to effect a sweeping of the inner walls of the former. By this means the separator element 200 is at all times maintained in a proper condition for operationand the danger from bursting due to built up dust deposits within it is eliminated.

The cleaner member 243 must be maintained in completely freely rotatable condition on the upper end of the shaft IIO if its function is to be maintained during continued service and, ac-

cordlngly, it is necessary to insure proper lubrication of its bearing surfaces on the shaft IIO. With this in view, the upper end of the cleaner element 243 is provided with a central recess 249'concentric with the shaft I I and into which the upper end of the bushing 248 projects. The interior of the recess 249 is filled with a mass of felt 250 or other material ofsimilar characteristics serving to absorb and hold lubricant. The bushing 248 preferably terminates below the upper end of the recess 249 so that the felt 250 may directly contact the shaft 0 thereabove and thereby aid ln carrying lubricant to the inner face of the bushing 248. Additionally, the surface of the bushing 248 within the recess 249 is provided on its exterior face with one or more axially parallel grooves 252 each communicating at its bottom with an opening 254 leading directly from the bottom of the recess 249 to the surface of the shaft I I0. In order to prevent lubricant absorbed by the felt 250 and thrown to the exterior thereof during rotation of the cleaner member 243 from escaping from the upperend of the recess 249, a washer member 258 is preferably sealed to the upper face ofthe member 243 at the outer edge of the recess 249 in overlying relationship to the upper face of the felt 258.

In Figs. 14, 15 and 16 modifications of the seal between the open end of the separator element 200 and the wall I36 are indicated. Outside of the change in the seal itself the construction is substantially the same as shown in the preceding flgures' except that the shaft 0 is replaced by a shaft M which terminates below the upper face of the separator element 200 and no separator cleaner element, such as 243 in the previous figures, is employed. Also, the bearing I48 in the previous views is replaced by a modified form of bearing M811 and the spider 236 is replaced by a modified form of spider 236a, b and 0 respectively. In these modifications the inner race of the bearing M is elongated as compared to the outer race thereof and the spider members 236a, b and c are clamped directly against its upper face by the lower face of a hollow post'member 210, the lower end of which is internally threaded for receiving the threaded upper end of the shaft 00 and thereby fix the spiders 236a, b and c in driving relation with respect to the shaft as well as locking itself to the shaft M for equal rotation therewith. The hollow interior of the post 210 is reduced in diameter at its upper end to form a shoulder 212 and its upper face is formed to provide a pilot 214 for reception in the central opening in the upper end of the separator element 200 through which the screw 202 projects in the previously described construction. A screw 216 projects upwardly from within the hollow interior of the post 210 through the shoulder 212 and above the upper face of the separator element 200 is threaded intoa semi-spherical nut member 218. A coil spring 280 surrounding the screw 216 and maintained under compression between the head thereof and the shoulder 212 constantly urges the nut member 218 downwardly so as to maintain the separator element 200 centered on the pilot 214 and frictionally clamped against the upper end of the post 210 so as to cause it to rotate equally with the post. It will be noted in Figs. 14, 15 and 16 that the fan blades 238 shown in connection with the spider member 236 of the upper housing member 38. The lower face of the outwardly ,turned flange 204 at the open end of the separator element 200, and the lower face of the rim of the spider 236a extend into substantially rubbing contact with the upper face of the ring 282' which thereby effects a seal between the flange 204 and the wall I36.

In Fig. the felt ring 282' is replaced by a narrower but thicker felt ring 286 and the re-- tainer member 284a corresponding to the retainer member 284 in Fig. 14 is upwardly stepped as at 288 to compensate for the added thickness of the felt ring. In this case the spider member 2361) is peripherally extended below the flange 204 of the separator element 200 into flush relationship with respect to the outer edge thereof and the outer edges of both the separator element 200 and the spider member 2361) are projected into a complementary groove 290 formed in the radially inner face'of the felt ring 286. Contact between the radially outer edge of the flange 204 and the radially inner face of the felt ring as in this construction is preferred over contact between axially directed faces as in Fig. 14 as less friction appears to develop in service.

It will be noted that in Figs. 14 and 15 the areas'of contact between the flange 204 of the separator element 200 and the felt ring lies radially outwardly beyond the outer face of the main body portion of the element 200, and this may be objectionable in some cases due to the fact that the friction set up at these areas of contact exerts a greater drag on rotation of the shaft II8a than would be the case if they were located at a smaller radial distance from the axis of the shaft 011.. In Fig. 16 a construction is illustrated in which substantially the same effect as is obtained in the construction shown in Fig. 15 may be obtained but in which the area of contact between the rotating part and the felt ring is located inwardly of the maximum diameter of the body portion of the separator element 200. In this construction the shoulder I38 on the wall I36 is positioned closer to the axis of the shaft IIOa than in the previously described construction, and received in the recess I40 against the shoulder I38is a felt ring 292 of still smaller width or radial dimension. The spider member 2360 in this case is provided at the inner edge of its rim with a downwardly projecting annular wall 294 terminating at its lower end in a radially outwardly directed flange or bead 296 located midway the depth of the felt ring 292 and contacting at its outer edge with the radially inner face of the ring 292. In this construction it will be noted that the area of contact between the bead 296 and the ring 292 occurs at a considerable less distance radially of the shaft IIiIa than in the constructions illustrated in Figs. 14 and 15 and consequently less frictional resistance to rotation of the shaft I I0 will result.

It has heretofore been explained in connection with the constructions thus far described that the air passing through the separator element 200 is so completely freed of dust and other foreign material that even though the additional filtering element 92 in the cap 44 was not employed the amount of dust carried on through the machine and discharged therefrom with the cleaned air would be negligible. However, there may be some instances where the degree of suction built up by the pumping mechanism is unusually great, or the character of the dust in the air being processed is such as to cause an appreciable amount of dust to be carried through the separator element 200, and in such cases it might require too frequent cleaning of the filter element 86 and removal of the upper layer of fabric 92 therefrom to be convenient, and in such cases a modification of the heretofore described constructions as illustrated in Figs. 17 to 20, inclusive, may be resorted to. The construction illustrated in these figures is identical to that disclosed in Figs. 1 to 13, inclusive, except in the following particulars. The upper frame member 36 in Fig. 2 is eliminated and the upper end of the main body portion 34 is formed to replace it. The wall I36 in this case is replaced by a wall 300 completely sealing the space between the ring I44 and the cylindrical opening 350. in the main body 34a.

A member 302 functioning in the same manner as the wall I36 as far as the seal between the casing and the open end of the separator element 200 is concerned is received within the opening 35a in superposed relation with respect to the wall 300 and upwardly spaced therefrom. The same plate member I84 is positioned below the wall 300 in spaced relation thereto.

In this modification a vertically extending cylindrical housing 306 is formed integrally with the main body portion 34a on each side of the body member 34a and partially located in the space between the main body portion 34a and the casing 32a. Each housing 306 is'closed at its bottom as indicated in Fig. 19 and in the present case the lower cap 440. is provided with an extension 308 below each of the housings 306 so as to continue the cylindrical effect thereof to the plane of the bottom of the device. Air discharge openings 3I0 are provided in these extensions instead of in the manner previously described, that is, in the present case the openings 3I0 communicate with the pockets I6 as illustrated in Figs. 2 and 10 but the pockets I6 are carried around and communicate with the hollow interior of the extension 308.

As illustrated in Figs. 19, 20 and 21, each housing 306 is provided on its inner face adjacent its upper end with an annular shoulder 3I2. An opening 3I4 is provided communicating the space between the wall 300 and the member 302 with the interior of each housing 306 above the shoulder 3I2 and an opening 3I6 communicating the interior of each housing 306 with the space between the wall 300 and the plate member I 84. Thus when the openings 3I4 and 3I6 are unrestricted, as indicated in Fig. 21, air flowing through the separator element 200 will be caused to pass between the wall 300 and member 302 through the opening 3I4 into the interior of the housing 306 and thence out through the opening 3I6 to the space between the wall 300 and the plate member I84 and then downwardly through the central opening in the plate I84 to the pumping mechanism in the manner previously described.

In the present case a ring member 3I8 is rotatably received within the upper end of each housing 306 and removably suspended therefrom in generally spaced relation with respect to the interior walls of the housing 306 is a stationary filter element in the form of a fabric or other bag 320. Preferably, a felt or other sealing ring 322 is provided between the shoulder 3I2 and the ring 3I8 to effect a more perfect seal between them. With this construction when the openings 3 I4 and 3I6 are unobstructed as indicated in Fig. 21, air flowing into the housing 306 through the opening 3I4 'will be caused to pass through the filter element 320 before it can be discharged through the opening 3I6 and in this manner substantially complete separation of all dust particles from the air being processed may be effected. Two of the housings 306 and corresponding filtering elements 320 are employed for the purpose of increasing the area of filtering material and lowering the velocity of the air passing through them.

The upper housing member 38a is formed to provide an opening over each of the housings 306 so as to enable the corresponding filtering element 320 to be removed therethrough for cleaning purposes. It is formed, however, to provide a radially inwardly directed circular flange 326 around such opening. At diametrically opposite points the flange 326 is provided with a notch 328. A cap member 330 provided with a shoulder 332 adapted to engage the upper face of the flange 326 through the intermediary of a suitable gasket 334 is provided with a downwardly projecting sleeve portion 336, and this sleeve portion 336 is provided with a pair of diametrically opposed, radially outwardly extending lugs 338 normally underlying the lower face of the flange 326 but which, when the cap 330 is turned to bring them into registry with the notches 328, may pass freely upwardly through the notches 328 to permit removal of the cap 330. The lugs 338 are preferably made of different Widths and the notches 328 of a width to correspond so that the cap 330 may be removed only when in one definite position of rotation.

The ring member 3I8 is provided at its upper edge with a pair of diametrically opposed, upwardly opening notches 340 therein in which the lower portions of the lugs 338 are received when the cap 330 is in operative position to close the upper end of the corresponding housing 306. The ring member 3I8 is provided with a downwardly projecting baffle portion 342 below one of the notches 340 therein and an upwardly projecting baflle portion 344 in vertical alignment therewith, the baifle portions 342 and 344 being arranged insubstantially contacting relation with respect to the corresponding inner wall portion of the housing 306. When the cap member 330 is turned to the position indicated in Figs. 19 and 20 so as to permit the lugs 338 to be drawn upwardly through the notches 328 and thus permit removal of the cap 330, the baffle 342 is positioned in overlying or blocking relationship with respect to the opening 3I6 and the baffle 344 in overlying or blocking relationship with respect to the opening 3I4, and when in such position these baflles block the flow of air between the separator element 200 and the pumping mechanism of the apparatus. Accordingly, whenever it is desired to remove a cap 330 to clean the corresponding filtering element 320, the cap 330 must be moved to the position indicated imFigs. 19 and 20 as a condition precedent to its removal and in so moving it automatically brings the baflles 342 and 344 into a position to prevent the flow of air through the apparatus. This prevents the possibility of dust being blown out of the housing 306 when the filters 320 are removed for cleaning in case the operator should inadvertently neglect to shut off the motor. Likewise, the caps 33!! must be moved .to locking position so as to effect a correct. seal between themselves and the cooperating shoulders 326 before it is possible for the machine to function correctly in use.

By the mechanism thus described not only is additional filtering area provided for the device, but it is provided in such a position as to eliminate what slight amount of dust. it may collect before the air being filtered by it reaches the pumping mechanism, and additionally it provides automatic means whereby it will. be impossible tocause dust to be blown from the housing 306 if it is inadvertently attempted toremove the filtering elements therefrom while the machine is operating.

It will be noted that in both of the main modiflcations of the principal structure herein disclosed the air inlet opening to which the end 94 of the flexible tube 96 is connected is located as near the floor or other supporting surface for the device as is reasonably practical. arranged forthe reason-that the user of the device will ordinarily attempt and wish to pull the filteringand actuating unit around on a floor by simply pulling on the tube 96, and should the point of connection between the tube and this unit be positioned at a higher point and the pull on the tube 96 be exerted from the side the device might readily be tipped over. By arranging the point of connection between the tube 96 and the operating unit as close as possible to I the floor and by rounding the lower edges of the lower cover 44 or a, as the case may be, particularly at the edge thereof adjacent the inlet opening, the operating unit may be pulled around a floor by a pull on the tube 96 with very little, if any, danger of tipping it over. As a further aid in preventing such tipping in the construction shown in Figs. 1 to 13, inclusive, laterally projecting foot members 350 may be provided on' the lower cap 44 for increasing the lateral dimensions of contact of the cap 44 with a supporting surface. In the construction illustrated in Figs. 1'7 to 21, inclusive, the extension 308 on the lower cap member a will serve a similar purpose.

It may also be noted that, while not necessary, it may be found of interest to the users of the device the upper housing member 38 or 38a, as the case may be, is provided with a relatively large opening352 as is seen in Fig. 2 above the separator element 200 and closed by a glass or other transparent wall 354 which will permit the user to observe the operation of the separator element 200 and the flow of dust laden air surrounding the same. Also, it is preferable to provide' a suitable-handlesuch as 356 by means of which the device may be readily picked up and carried from place to place.

Formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensulationship with respect to a peripheral surface ,1

thereof, means for causing air to be processed by said separator element to flow inwardly through said separator element in a direction toward the interior thereof, and means tending to cause a- I portion of the air processed by said separator-ele- This is so i ment to flow outwardly therefrom through the 6 space between said surface and wall to thereby seal said space against the flow of unprocessed air therethrough.

.2. In combination, a rotatable separator element, a wall associated" in spaced but adjacent relationship with respect to a peripheral surface thereof, means for causing air to be processed by said separator element to flow inwardly through said separator element in a direction toward the interior thereof and tending to draw air not processed by said separator through the space bethereof, means for causing air to be processed by said separator element to flow through said separator element in a direction toward the interior thereof, and means comprising a motor driven fan element having radially extending blades, the tipsof which extend into proximity with respect to said peripheral surface tending to cause a portion of the air processed by said separator element to flow outwardly therefrom through the space between said surface and wall tothereby seal said space against the flow of unprocessed air therethrough.

4. An air cleaner structure including, in combination, a casing, a dividing wall in said casing provided with an opening for the passage of air therethrough, pumping mechanism in said casing on one sideof saidwall, a rotatable separator element in said casing on the other side of. said wall, common means for driving, said pumping means and said separator elementv to draw air inwardly through said separator element, said separator having an edge extending in spaced but adjacent relationship with respect to said wall, and means driven by the first mentioned means tending to force air outwardly from said separator element through the space between said edge and said wall.

5. An air cleaner structure including, in combcination, a casing provided with an apertured wall dividing it into two compartments, a ro-- tatable shaft projecting through said wall, an air pump in one of said compartments driven from said shaft and adapted to move air through said casing and wall, an air separator in the other of said. compartments driven from said shaft, an edge on said separator extending into spaced but adjacent relation with respect to said wall, and a fan element arranged for rotation with said separator and so constructed and arranged as to tend to discharge air from the.

interior of said separator through the space between said edge and. wall and thereby seal said space against the entrance of air therethrough in a reverse direction.

. 6. In an air cleaner structure, in combination, a casing, a. dividing wall in said casing separating the interior thereof into a pair of compartments and having an opening therein for the flow of air between them, a shaft in said casing, a motorfor driving said shaft, a separator element in one of said compartments secured in driving relation with respect to said shaft and in overlying relation with respect to said opening for processing air flowing between 'said compartments, said separator element having a peripheral edge extending into spaced but adjacent relation with respect to said wall, a multi-stage air pump in the other of said compartments secured in driving relation to said shaft for causing air to flow thereinto from the first mentioned compartment and through said element, and means driven from said shaft tending to neutralize the effect of the suction ofsaid pump in the space between said edge and said wall.

7. In an air cleaner, in combination, a casing having a wall therein, a rotatable shaft in said casing, an air separator element secured in driving relation to said shaft and having a radially disposed edge portion, air pumping mechanism secured in driving relation to said shaft for the purpose of causing a flow of air through said air separator element, and means for sealing said edge of said air separator element with respect to said wall of said casing comprising a ring of felt sealed to said wall and in substantial rubbing relation with respect to said edge.

8. In an air cleaner, in combination, a casing having a wall, a rotatable shaft in said casing,

ill

an air separator element secured in driving relation to said shaft, said air separator element having a radially directed edge of. less diameter than the maximum diameter of said element, an

air pumping mechanism secured in driving relation to said shaft in axially displaced relation with respect to said air separator element, and means for limiting the flow of air between said element and said pumping mechanism through said element only comprising a felt element sealedto said wall of said casing and extending into substantial rubbing contact with respect to said radially directed edge.

9. In an air cleaner mechanism, in combination, a casing, a rotatable shaft in said casing, a cup-shaped air separator element secured in driving relation with respect to said shaft, the open end of said element being directed in a radially inward direction, and means sealed to a wall of said housing extending into sealing relation with respect to said inwardly directed end of said element.

10. In an air cleaner, in combination, a rotatable separator element of. the type depending upon' rotation 'to effect separation of dust from air, means for driving said element, and a separator cleaner member within said separator element normally rotatable therewith but freely rotatable relative thereto.

11. In an air cleaner, in combination, a rotatable separator element of the type depending upon rotation to effect separation of dust from air, means for driving said element, means for causing a flow of air through said element, and freely rotatable means extending into closely adjacent relationship to the issuing air stream side of said element for preventing dust from building up on said side of said element.

12. In an air cleaner, in combination, a rotat able shaft, a shell-like air separator element of the'type depending upon rotation to effect separation of dust from air secured in driving relation thereto, means for causing air to flow through said separator element in the direction of the outside toward the inside thereof, and an element rotatably mounted relative to said shaft within said separator element and having a part extending into close but spaced relationto the inner periphery of said separator element.

13. In an air cleaner, in combination, a. rotatable shaft, a shell-like air separator element of the type depending upon rotation to effect separation of dust from air secured in driving relation thereto, means for causing air to flow through said separator element in the direction of the outside toward the inside thereof, and an element rotatably mounted relative to said shaft within said separator element, the last mentioned element having a plurality of radially extending vanes extending into close but spaced relation to the inner periphery of said separator element whereby upon relative rotation between said elements said vanes will act to sweep said inne periphery.

14. In an air cleaner, in combination, a vertically extending rotatable shaft, a cup-shaped air separator element secured thereto for driving movement therefrom, an inertia separator cleaner member rotatably mounted on said shaft within said element, said member having an annular recess formed in its upper face and having restricted communication only with said shaft except at the upper end thereof, absorbent material filling said recess, and an annular flange sealed to said member at the upper end of the outer wall of said recess.

15. In an air cleaner, in combination, a vertically extending rotatable shaft, a cup-shaped air separator element secured thereto for driving movement therefrom, an inertia separator cleaner member rotatably mounted on said shaft within said element,said member having an opening centrally formed in its upper face to form a pocliet therein about said shaft, a bushing in said member for said shaft, said bushing having an opening therethrough. at the bottom of said pocket and projecting upwardly into said opening to a point below the upper edge thereof, lubricant absorbent material filling said opening, and an annular radially inwardly extending fiange sealed to said member at the upper end of said opening and overlying said material.

16. A rotatable dust separator element adapted for the flow of air therethrough comprising a circular shell of sheet metal the peripheral wall of which is sinuously curved and slotted at the radially inner surface of the curves thereof.

17. A rotatable dust separator element adapted for the fiow of air therethrough comprising a generally circular sheet metal shell the'periphery of which is formed to provide a plurality of alternately oppositely radially facing grooves, the outwardly facing grooves being slotted at their bottoms.

18. A rotatable dust separator element adapted for the flow of air therethrough comprising a generally circular sheet metal shell the periphery of which is formed to provide a plurality of alternately oppositely facing helically disposed grooves, the outwardly-facing grooves being slotted at their bottoms.

' 19. In an air cleaner, in combination, a pair of casings arranged in generally side-to-side relationship and in open communication with each other at the upper ends thereof by a singlepassage, a vertically extending shaft in one of said casings, an air separator element secured to said shaft in the upper portion of the corresponding casing, said corresponding casing having an air inlet adapted'to discharge air thereinto adjacent the plane of said airseparator element and an opening in the lower portion thereof for the discharge of air therefrom, means in said corresponding casing secured in driving relation to said shaft for causing air to flow from said inlet opening through said separator element and then out through said discharge opening, and means for driving said shaft, the other of said casings being closed except for said passage and providing a dead'air separated out by said air separator element from 0nd casing being impervious to the the air flowing through said corresponding casing.

20. In an air cleaner, in combination, a casing having an inlet opening at its upper end and a discharge opening at its lower end, means for causing air to flow'through'said casing from said" inlet toward said outlet, a rotatable air separator element in said casing adjacent said inlet, a second casing positioned in adjacent relationship with respect to the first casing and in open communication with the first mentioned casing only in the plane of said separator element, said secpassage of air therethrough. h

21. In an air cleaner, in combination, a casing, a vertically extending shaft in said casing, a ro-.

tatable air separator element secured in drivingrelation to said shaft in the upper portion of said casing, said casing having an air inlet opening opening into the interior thereof adjacent said air separator element and in a direction approxi-- mately tangential with respect to'the outer surface of said air separatorelement, said casing having an air discharge port in the lower portion thereof, means secured in driving relation with respect to said shaft below said air separator element for causing air to flow through said casing and air separator element, and a second casing forming a dead air space arranged in adjacent relationship with respect to the first mentioned casing, the upper end of said second casing being in open communication with the upper end of the first mentioned casing "by means of a passage tangentially arranged with respect to the outer surface of said air sepa'ratorelement but in the opposite sense with respect to the tangential arrangement of said air inlet opening.

.22. In an air cleaner, in combination, a casing having an inlet and an outlet opening, a rotatable air separator element positioned between said inlet and said outlet, means for causing a flow of air through said casing, means for driving the last mentioned means and said air separator element, a second casing in open communication with 'air in the first mentioned casing between said air separator element and said inlet opening providinga zone'of quiescence for the reception and collection of dust separated out from air flowing through the casing by said air separator element, and a fixed filtering element interposed between said air separator element and said outlet opening.

23. In an air cleaner,in combination, a casing having an inlet and an outlet opening,'a rotatable air separator element positioned in said casing between said inlet and said outlet, a pumping mechanism positioned within said casing between said air separator element and said outlet,"

said air separator element and said inlet opening providing a zone of quiescence for receiving and storing foreign material separated out from air flowing through said casing by said air separator element, a fixed filtering element interposed in the path of flow between said air separator element and said pumping mechanism, and a second fixed filtering element interposed between said pumping mechanism and said discharge opening.

.and said outlet, a pumping mechanism within space for the reception and collection 'of dust-.'

said casing for causing a flow of air between said inlet and said outletthrough said air separator. element, means for driving said pumping mechanism and said air separator element, a chamber in open communication with said casing between,

said air separator element and said inlet opening affording a zone of quiescence for receiving and storing foreign material separated out from air flowing through said casing by said air separator element, a stationary filtering element disposed in the path of flow of air between said air separator element and said pumping mechanism, said casing having a removable cover through which said stationary filtering element is removable from said casing, and means associated with said casing between said air separatorelement and said outlet for causing a flow of air therethrough, means for driving said 'air separator element and said pumping mechanism, a chamber in open communication with 'the interior of said casing between said air separator element and said inlet opening, a second chamber arranged in the path of flow of air through said casing between said air separator element and said pumping mechanism, means movable to block the flow of air through said second chamber, a stationary filtering element positioned in the path of flow through said second chamber, a removable cover element for said second chamber through which said stationary filtering element is removable, said cover being so constructed and arranged with respect to said blocking means as to move said blocking means into blocking position as a condition precedent to removal of said cover'.

26. In an air cleaner, in combination, a casing having an inlet and an outlet, a rotatable'air separator element arranged'in said casing between said inlet and said outlet, an air pumping air separator element and said outlet, means for driving said air separator element and said pumping mechanism, a chamber in open com- .munication with the interior of said casing between said air separator element and said inlet providing a zone of quiescence for receiving and storing foreign material separated out from the air flowing through said casing by said air separator element, a second chamber positioned in the fiow of air between said air separator element and said pumping mechanism, a stationary filter element disposed in the path of flow of air through said second chamber, and a noise muffiing element positioned in the path of flow between said pumping mechanism and said outlet.

27. In an air cleaner, in combination, a casing, a vertically extending shaft in said casing, a rotatable u air separator element and a pumping mechanism arranged within said casing and drivingly connected to said shaft in axially spaced relation, means for driving said shaft, said casing being formed'to provide an inlet and an 1 said casing being so constructed and arranged adjacent the point of opening of said inlet opening on the outer face thereof as to permit the connection of a cleaner nozzle hose to said casing, and the bottom surface of said air cleaner being especially formed by upwardly curving the same at the side thereof at which said inlet is located for sliding contact with a supporting surface.

28. In an air cleaner, in combination, a casing having a hinged bottom cover and a latch mechanism for maintaining the cover in normally closed position, said air cleaner having an inlet opening and said cover having an outlet opening, a vertically extending shaft in said casing, a rotatable air separator element secured in driving relation to said shaft between said inlet and said outlet, pumping mechanism drivingly connected to said shaft within said casing between said air separator element and said outlet, an electric motor within said casing for driving said shaft including an armature fixed to said shaft, a bearing for the lower end of said shaft supported by said casing, an upwardly opening pocket formed centrally in said cover for reception of said hearing when said cover is in closed position, and a stationary filtering element supported about said pocket in spaced relation to the bottom of said cover and interposed in the path of flow of air between said pumping mechanism and said outlet.

29. In a vacuum cleaner an enclosing housing, a partition wall dividing said housing into separate chambers, an aperture through said partition, a shaft extending through said aperture, means for driving said shaft, a rotary dust separator mounted on said shaft in one of said chambers, said separator having a flange lying closely adjacent the peripheral edge of said aperture, pumping mechanism driven by said shaft located in the other of said chambers serving to draw air from said first mentioned chamber through said rotary dust separator into said last mentioned chamber, and means on said flange tending to draw air from the chamber housing said pump into the chamber housing, said dust separator whereby flow of air through the space between said separator and partition into the chamber enclosing said pump is precluded.

30. In a vacuum cleaner an enclosing housing, a partition wall dividing said housing into separate chambers, one adapted to house a pump and the other adapted to house a separator, an aperture affording communication between said chambers, a rotary dust separator element in said separator chamber having a flange lying adjacent the edge of said aperture, 2. pump in said pump chamber adapted to draw air from said separator chamber through said separator into said pump chamber, means for driving said pump and separator and means on said flange tending to draw air from said pump chamber into said separator chamber through the space between said flange and said partition thus pre cluding the entry of air into the pump chamber at this point.

31. In a vacuum cleaner an enclosing housing, a partition wall dividing said housing into separate chambers, one adapted to house a pump and the other adapted to house a separator, an aperture affording communication between said chambers, a rotary dust separator element in said separator chamber having a flange lying adjacent the edge of said aperture, a pump in said pump chamber adapted to draw air from said separator chamber through said separator into said pump chamber, means for driving said pump and separator and means on said flange.

tending to draw air from'said pump chamber into said separator chamber through the space between said flange and said partition thus precluding the entry of air into the pump chamber at this point, said last mentioned means including a plurality of vanes.

FWTCE' A. BROOK. 

